Color: Black - Open/Closed Sign Clear and Eye-Catching: The font is clearly printed with a red background on one side and a green background on the other. The color contrast ensures high visibility. Magnetic and Adhesive: Two installation options: directly onto magnetic surfaces or using the included adhesive tape for non-magnetic surfaces. Easy and tool-free installation. Portable and Durable: Made of durable aluminum with a high-quality acrylic interior. Lightweight, portable, waterproof, and more durable than plastic. Quick Changes: This sliding door sign displays two modes. The slider easily glides to show 'Open' or 'Closed' when placed horizontally. Versatile: Suitable for shop doors, office doors, meeting rooms, home offices, and study rooms. Also suitable for outdoor use, recording studios, and public service buildings. The slider clearly indicates whether the room is open or closed.